"* Made progress using Trebor's Tables to find inferences about the puzzle. A total of 9574 implications about the puzzle were generated and examined in order to find these inferences - you'd run through several pencils working them out by hand!"

"* Made progress using Trebor's Tables to find inferences about the puzzle. A total of 9574 implications about the puzzle were generated and examined in order to find these inferences - you'd run through several pencils working them out by hand!"

You have an out-of-date version of Susser. The current version is 2.5.0 -- and it solves this puzzles using "only" comprehensive forcing chains.